Nitrogen and phosphorus are polluting US waters, creating algae blooms and dead zones. New research confirms that voluntary steps are failing in the Gulf of Mexico and unlikely to work in Lake Erie.
Excess nutrients from farm fields cause widespread water pollution across the U.S. Bioreactors -- essentially, ditches filled with wood chips -- are emerging as a way to reduce nutrient pollution.
Too much fertiliser can kill all life in parts of the ocean. It has happened before – and could do so again.
The same conditions – ultimately tied to nutrient runoff – that created the damaging toxic blooms and dead zones in US waterways of recent years are forecast to return this year.